Apparatus for detecting digital video signal parameters and method thereof

1. An apparatus for detecting a plurality of digital video signal parameters used in an Orthogonal Frequency-Division Multiplexing (OFDM) communication system, the apparatus receiving a first Orthogonal Frequency Division Multiplexing (OFDM) symbol and a second OFDM symbol to detect an integer carrier frequency offset (ICFO), a pilot pattern and a carrier mode of a received signal, the first OFDM symbol comprising a plurality of first frequency-domain sub-carriers, the second OFDM symbol comprising a plurality of second frequency-domain sub-carriers, the apparatus comprising:

a correlation apparatus that generates a plurality of sub-carrier correlation results according to a plurality of predetermined ICFOs, a predetermined pilot pattern, a predetermined carrier mode, and a plurality of correlation values generated from correlating the first frequency-domain sub-carriers and the second frequency-domain sub-carriers, the correlation apparatus comprising:

a correlator that complex-conjugate multiplies the plurality of first frequency-domain sub-carriers by the plurality of second frequency-domain sub-carriers to generate the plurality of correlation values;

a storage unit, coupled to the correlator, that stores the plurality of correlation values;

an address generating unit, coupled to the storage unit, that generates a plurality of sub-carrier addresses according to the plurality of predetermined ICFOs, the predetermined pilot pattern, and the predetermined carrier mode; and

an adding unit, coupled to the storage unit, that generates the sub-carrier correlation results from the absolute value of a summation of the plurality of correlation values corresponding to the plurality of sub-carrier addresses;

a maximum value searching unit, coupled to the correlation apparatus, that determines a maximum sub-carrier correlation result from the plurality of sub-carrier correlation results; and

a parameter generator, coupled to the maximum value searching unit, that generates the ICFOs, the pilot pattern and the carrier mode in response to the maximum sub-carrier correlation result.

2. The apparatus as claimed in claim 1 , wherein the address generating unit comprises a shifter that generates the plurality of predetermined ICFOs.

3. The apparatus as claimed in claim 2 , wherein the address generating unit further comprises a pilot pattern address generator, coupled to the shifter, that generates the predetermined pilot pattern.

4. The apparatus as claimed in claim 3 , wherein the pilot pattern address generator selects the predetermined pilot pattern according to a Fast Fourier Transform (FFT) size and a guard interval.

5. The apparatus as claimed in claim 3 , wherein the pilot pattern address generator selects the predetermined carrier mode according to a Fast Fourier Transform (FFT) size.

6. The apparatus as claimed in claim 1 , wherein the OFDM communication system has a continual pilot pattern at a continual pilot address, and wherein each of the plurality of sub-carrier addresses is generated by adding the continual pilot address to each of the predetermined ICFOs.

7. The apparatus as claimed in claim 1 , wherein the carrier mode comprises a normal carrier mode.

8. The apparatus as claimed in claim 7 , wherein the carrier mode further comprises an extended carrier mode.

9. A method for detecting a plurality of digital video signal parameters, including an integer carrier frequency offset (ICFO), a pilot pattern and a carrier mode of a received signal in an Orthogonal Frequency Division Multiplexing (OFDM) communication system, the method comprising:

receiving a first OFDM symbol and a second OFDM symbol, the first OFDM symbol comprising a plurality of first frequency-domain sub-carriers, the second OFDM symbol comprising a plurality of second frequency-domain sub-carriers;

generating a plurality of sub-carrier correlation results according to a plurality of predetermined ICFOs, a predetermined pilot pattern, a predetermined carrier mode, and a plurality of correlation values generated from correlating the first frequency-domain sub-carriers and the second frequency-domain sub-carriers;

determining a maximum sub-carrier correlation result from the sub-carrier correlation results; and

outputting the ICFO, the pilot pattern, and the carrier mode in response to the maximum sub-carrier correlation result,

wherein each of the sub-carrier correlation results is an absolute value of a summation of the correlation values corresponding to the predetermined ICFO, the predetermined pilot pattern, and the predetermined carrier mode.

10. The method as claimed in claim 9 , wherein each of the correlation values is a complex-conjugate product of each of the first frequency-domain sub-carriers by each of the second frequency-domain sub-carriers.

11. The method as claimed in claim 9 , further comprising selecting the predetermined pilot pattern according to a Fast Fourier Transform (FFT) size and a guard interval.

12. The method as claimed in claim 9 , further comprising selecting the predetermined carrier mode according to a Fast Fourier Transform (FFT) size.

13. The method as claimed in claim 9 , wherein the carrier mode comprises a normal carrier mode and an extended carrier mode.